1) Is the Department of Defense (DoD) pursuing an improved anthrax vaccine?

Yes. DoD is actively pursuing a next-generation anthrax vaccine (NGAV) in cooperation with the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH).

2) Why is DoD pursuing another anthrax vaccine? Doesn’t the one you have now work?

The National Academy of Sciences and its Institute of Medicine (IOM) stated in no uncertain terms that “AVA [the current FDA-licensed anthrax vaccine], as licensed, is an effective vaccine to protect humans against anthrax, including inhalational anthrax." This was in its March 2002 report, which can be found at: http://www.nap.edu/catalog/10310.html.

3) Then why are you pursuing a next-generation anthrax vaccine?

We want to explore whether a newer anthrax vaccine would be easier to produce and require fewer doses to achieve immunity. The IOM study also recognized the advantages of developing a next-generation anthrax vaccine when it said, “the production, testing, and licensure of a new vaccine requiring fewer doses and producing fewer local reactions are needed.” Aviators consistently seek better airplanes. Similarly, we seek better vaccines.

4) What efforts does DoD have underway? Who are DoD’s partners?

DoD and the National Institutes of Health (NIH) have been working on a next-generation anthrax vaccine (NGAV). Specifically, the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) and the Joint Vaccine Acquisition Program (JVAP) collaborated to develop an NGAV that uses state-of-the-art recombinant technology. The NIAID collaborates with this effort by preparing the NGAV product and sponsoring human clinical phase-1 trials. The NIAID is independently pursuing multiple “recombinant protective antigen” (rPA) candidate vaccines, to identify and develop the most promising next-generation vaccine as quickly as possible. This is a parallel effort from the DoD/NIAID cooperative effort on the DoD NGAV candidate.

5) What advantages could an NGAV offer?

NGAV is a much more highly defined product (a single highly purified protein). As a result, there should be more consistency from production lot to production lot, making release testing more predictable. Additionally, it might be possible to achieve immunity with fewer doses, because higher and more consistent doses of the protective-antigen protein may be administered. It might also be possible to use an intramuscular injection route, which may cause fewer adverse events after vaccination (i.e., be less reactogenic). However, this possibility won’t be known until human clinical trials of the vaccine are completed. Finally, the rPA is produced in non-sporeforming bacteria that permit the vaccine to be made in the same production facility as other vaccines, unlike anthrax vaccine adsorbed (AVA).

6) How will this new anthrax vaccine be produced?

The next-generation anthrax vaccine (NGAV) is based on a protein called “recombinant protective antigen” (rPA). rPA is a single purified protein that protects animals against aerosol exposure to deadly Bacillus anthracis spores. rPA can be produced in several genetically-engineered bacteria

7) Will a next-generation anthrax vaccine protect as well as the current anthrax vaccine?

That is our goal, yes. Until completion of human clinical trials, we do not know how much protective antibody human volunteers will produce. Preliminary data from non-human primates (rhesus monkeys) seems to indicate similar protection profiles compared to anthrax vaccine adsorbed (AVA).

8) What has to be done before we can use an NGAV?

NIH is in the beginning stages of clinical testing of an NGAV. Phase I tests in a few dozen people will study this new vaccine’s safety. Next, a preliminary Phase II test in a few hundred people will test antibody responses to the new vaccine. Expanded Phase III testing among thousands of volunteers will produce pivotal information about both safety and immune responsiveness required for product licensing. Advanced studies (post-clinical trials) will be conducted in animals to define the protective immune response induced by the NGAV candidate. Additionally, studies will be performed to optimize the vaccine’s formula and immunization schedule. In addition, results from the study of the current FDA-licensed anthrax vaccine, being conducted by the Centers for Disease Control & Prevention (CDC), will provide critical information on immune responses that will be required to license an NGAV. Finally, the FDA will study all of the data and eventually determine if the NGAV will become a licensed product.

9) When will human clinical trials of next-generation anthrax vaccines (NGAV) begin?

These clinical trials began in fall 2002.